1. Field of the Invention
The present invention pertains to the field of mechanics, and more specifically to the field of fluid mechanics. In particular, the invention is directed to a pyrotechnically actuated, hermetically sealed, dual air valve that is inoperative until activated to concomitantly provide two separate air pressure differentials.
2. Description of the Prior Art
An erecting type air pressure probe that uses a pyrotechnically actuated, hermetically sealed dual air valve is known to be used in a missile environment. Although sufficient for its designed purpose, this erecting type air pressure probe is inherently limited in its applications in that it is necessary that the air probe be extended from a missile exterior skin to be activted. In a confined environment such as where a missile is being deployed from a launching tube, substantial missile and/or tube damage, or an aborted firing, could be incurred if the air pressure probe should inadvertently be erected through the missile skin while the missile is still in its launching tube.
Other probe designs have used stored mechanical energy, such as preloaded springs, or lanyards attached between the probe assembly and the missile launching apparatus to activate the probe after the missile has travelled a predetermined distance from the launcher. Some configurations have included external tear strips attached by a lanyard to the launching apparatus. When the tear strips are torn away, the probe mechanism is exposed which then activates the fuze system.
Actuation mechanisms using external hardware or external probe air scopes are useful in air launched missiles, but cannot be used in surface launched or tube launched missiles where external structures or probes interfere with the launcher.
Other prior art devices have generally described gas actuated cartridges used to move a sliding member (piston) in a valve housing (cylinder) to open an internal valve which then allows fluid to flow through the valve.
In view of the prior art, there remains a long felt need for an electronically controlled, pyrotechnically actuated, hermetically sealed, dual air valve capable of being positioned within a missile body remotely oriented from a missile's external air inlets and obtaining its air pressure sources internal to the missile.